how to move cursor between viewports while extruding
Thanks for your reply! Well, it seems like I was fooled by the hidden efficiency of Blender: When I finish an extrude (left click), the new edge is still marked, so just scooting over to another viewport and pressing G will just shuffle that new edge around in another direction, like the extrude continued there. I totally missed out that the newly created edge is as movable as any other selected part. (Old Solid CAD modeller here, hard to get used to this...)